Ruler



FIG. 1 is a bottom plan view of a ruler showing our new design;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is an enlarged right side elevation view thereof; and,

FIG. 6 is an enlarged left side elevation view thereof. 

The ornamental design for a ruler, as shown and described. 